Maresin-2 promotes mucosal repair and has therapeutic potential when encapsulated in thermostable nanoparticles.

Resolution of inflammation and mucosal wound healing are crucial processes required to re-establish homeostasis following injury of mucosal tissues. Maresin-2 (MaR2), a lipid specialized pro-resolving mediator derived from omega-3 polyunsaturated fatty acid, has been reported to promote resolution of inflammation. However, a potential role for MaR2 in regulating mucosal repair remains undefined. Using lipidomic analyses, we demonstrate biosynthesis of MaR2 in healing intestinal mucosal wounds in vivo. Importantly, administration of exogenous MaR2 promoted mucosal repair following dextran sulfate sodium-induced colitis or biopsy-induced colonic mucosal injury. Functional analyses revealed that MaR2 promotes mucosal wound repair by driving intestinal epithelial migration through activation of focal cell-matrix adhesion signaling in primary human intestinal epithelial cells. Because of its labile nature, MaR2 is easily degradable and requires ultracold storage to maintain functionality. Thus, we created thermostable polylactic acid MaR2 nanoparticles that retain biological activity following extended storage at 4 °C or above. Taken together, these results establish MaR2 as a potent pro-repair lipid mediator with broad therapeutic potential for use in promoting mucosal repair in inflammatory diseases.

A Rapid Self-Assembling Peptide Hydrogel for Delivery of TFF3 to Promote Gastric Mucosal Injury Repair.

Self-assembled peptide-based nanobiomaterials exhibit promising prospects for drug delivery applications owing to their commendable biocompatibility and biodegradability, facile tissue uptake and utilization, and minimal or negligible unexpected toxicity. TFF3 is an active peptide autonomously secreted by gastric mucosal cells, possessing multiple biological functions. It acts on the surface of the gastric mucosa, facilitating the repair process of gastric mucosal damage. However, when used as a drug, TFF3 faces significant challenges, including short retention time in the gastric mucosal cavity and deactivation due to degradation by stomach acid. In response to this challenge, we developed a self-assembled short peptide hydrogel, Rqdl10, designed as a delivery vehicle for TFF3. Our investigation encompasses an assessment of its properties, biocompatibility, controlled release of TFF3, and the mechanism underlying the promotion of gastric mucosal injury repair. Congo red/aniline blue staining revealed that Rqdl10 promptly self-assembled in PBS, forming hydrogels. Circular dichroism spectra indicated the presence of a stable ß-sheet secondary structure in the Rqdl10 hydrogel. Cryo-scanning electron microscopy and atomic force microscopy observations demonstrated that the Rqdl10 formed vesicle-like structures in the PBS, which were interconnected to construct a three-dimensional nanostructure. Moreover, the Rqdl10 hydrogel exhibited outstanding biocompatibility and could sustainably and slowly release TFF3. The utilization of the Rqdl10 hydrogel as a carrier for TFF3 substantially augmented its proliferative and migratory capabilities, while concurrently bolstering its anti-inflammatory and anti-apoptotic attributes following gastric mucosal injury. Our findings underscore the immense potential of the self-assembled peptide hydrogel Rqdl10 for biomedical applications, promising significant contributions to healthcare science.

YAP regulates intestinal epithelial cell proliferation through activation of STAT3 in DSS-induced colitis and associated cancer. / YAP蛋白通过激活STAT3è°ƒæŽ§è‚ ä¸Šçš®ç»†èƒžå¢žæ®–åœ¨DSSè¯±å¯¼è‚ ç‚ŽåŠç›¸å ³è‚ ç™Œä¸­çš„ä½œç”¨.

OBJECTIVES: Ulcerative colitis (UC) is a chronic, relapsing inflammation of the colon. Impaired epithelial repair is an important biological features of UC. Accelerating intestinal epithelial repair to achieve endoscopic mucosal healing has become a key goal in UC. Yes-associated protein (YAP) is a key transcriptional coactivator that regulates organ size, tissue growth and tumorigenesis. Growing studies have focused on the role of YAP in intestinal epithelial regeneration. This study explore the molecular mechanism for the role YAP in modulating colonic epithelial proliferation, repair, and the development of colitis associated cancer. METHODS: We constructed the acute colitis mouse model through successive 5 days of 3% dextran sulfate sodium salt (DSS) induction. Then YAP-overexpressed mouse model was constructed by intraperitoneal injection the YAP overexpressed and negative control lentivirus into DSS mice. On the 5th day of DSS induction and the 5th day of normal drinking water after removing DSS (5+5 d), the mice were killed by spinal dislocation. The colon was taken to measure the length, and the bowel 1-2 cm near the anal canal was selected for immunohistochemical and Western blotting. We used YAP over-expressed colonic epithelial cells and small interfering signal transducer and activator of transcription 3 (STAT3) RNA to probe the regulation of YAP on STAT3, using cell counting kit-8 and scratch assays to explore the role of YAP on colonic epithelial cell proliferation. Finally, we conducted co-immunoprecipitation to test the relationship between YAP and STAT3. RESULTS: After DSS treatment, the expression of YAP was dramatically diminished in crypts. Compared with the empty control mice, overexpression of YAP drastically accelerated epithelial regeneration after DSS induced colitis, presenting with more intact of structural integrity in intestinal epithelium and a reduction in the number of inflammatory cells in the mucosa. Further Western blotting, functional experiment and co-immunoprecipitation analyses showed that the expression of YAP in nucleus was significantly increased by 2 h post DSS cessation, accompanied with up-regulated total protein levels of STAT3 and phosphorylated-STAT3 (p-STAT3). Overexpression of YAP enhanced the expression of STAT3, p-STAT3, and their transcriptional targets including c-Myc and Cyclin D1. In addition, it promoted the proliferation and the "wound healing" of colonic cells. However, these effects were reversed when silencing STAT3 on YAP-overexpressed FHC cells. Moreover, protein immunoprecipitation indicated that YAP could directly interact with STAT3 in the nucleus, up-regulatvng the expressvon of STAT3. Finally, during the process of CAC, overexpression of YAP mutant caused the down-regulated expression of STAT3 and inhibited the development and progress of CAC. CONCLUSIONS: YAP activates STAT3 signaling in regulation of epithelial cell proliferation and promotes mucosal regeneration after DSS induced colitis, which may serve as a potential therapeutic target in UC. However, persistent and excessive YAP activation may promote CAC development.

Hepatocyte Growth Factor Facilitates Esophageal Mucosal Repair and Inhibits the Submucosal Fibrosis in a Rat Model of Esophageal Ulcer.

BACKGROUND/AIMS: Esophageal mucosal damage often causes scar tissue, leading to refractory stricture. The aim of this study was to clarify the effect of hepatocyte growth factor (HGF) on esophageal mucosal repair and fibrosis leading to stricture in a rat model of esophageal ulcer. METHODS: Esophageal ulcers were induced in rats by topical exposure of the lower esophageal serosa to acetic acid, followed by intraperitoneal administration of HGF (200 µg/day) using an osmotic pump for 7 days. The effect of HGF on esophageal mucosal injury was investigated macroscopically and microscopically. The effect of HGF on epithelial cell proliferation and the expression of genes closely associated with the development of fibrosis were also examined. RESULTS: The administration of HGF for 7 days led to a significant reduction in the ulcerative area and enhanced the proliferation of esophageal epithelial cells. HGF treatment significantly decreased the fibrosis, and subsequently attenuated not only the foreshortening but also the narrowing of the esophagus. The expression levels of tissue inhibitor of metalloproteinase (TIMP)-1, -2, and matrix metalloproteinase (MMP)-2, -9 were significantly decreased among rats treated with HGF. CONCLUSION: HGF facilitates the repair of esophageal mucosal injury and may also ameliorate the esophageal fibrosis, possibly through enhanced re-epithelization.

Effect of vedolizumab (anti-α4ß7-integrin) therapy on histological healing and mucosal gene expression in patients with UC.

OBJECTIVE: Lymphocyte recruitment to the inflamed gut is increased in UC. Inhibition of this cell trafficking by vedolizumab (VDZ) was successful in inducing and maintaining remission and in induction of endoscopic mucosal healing. There are no data on histological healing with VDZ. We studied histological changes following VDZ therapy and compared gene expression in patients with UC before and after therapy. DESIGN: Forty-one patients with UC from GEMINI I and LTS were studied before and at three time points (weeks 6/12/52) following VDZ therapy. Colonic biopsies were scored using the Geboes index and correlated with Mayo endoscopic subscore. Gene expression was analysed using Affymetrix gene arrays. RESULTS: Fifty-five per cent of patients achieving endoscopic healing (= Mayo endoscopic subscore 0-1) with VDZ at the studied time points also had histological healing (= Geboes grade 0-1). In most healers, some residual histological changes (eg, disturbed architecture and increased mononuclear cell infiltrate) were still observed, although this was less at week 52. VDZ restored expression of many inflammatory genes in patients with endoscopic healing only at week 52 and not before. In VDZ healers, the expression of many genes remained dysregulated at weeks 6/12/52 compared with controls. CONCLUSIONS: VDZ induces histological healing in >50% of patients with endoscopic healing, with maximal effect at week 52. VDZ also restored, although incompletely, the colonic expression of many immune-related genes in patients with UC achieving endoscopic healing at week 52. However, persistent histological and gene dysregulations did remain even in healers, suggesting that maintenance therapy will be necessary to control the intestinal inflammation. TRIAL REGISTRATION NUMBERS: NCT00783718 and NCT00790933; post-results.

ß-PIX plays an important role in regulation of intestinal epithelial restitution by interacting with GIT1 and Rac1 after wounding.

Early gut mucosal restitution is a process by which intestinal epithelial cells (IECs) migrate over the wounded area, and its defective regulation occurs commonly in various critical pathological conditions. This rapid reepithelialization is mediated by different activating small GTP-binding proteins, but the exact mechanism underlying this process remains largely unknown. Recently, it has been reported that interaction between p21-activated kinase-interacting exchange factor (ß-PIX) and G protein-coupled receptor kinase-interacting protein 1 (GIT1) activates small GTPases and plays an important role in the regulation of cell motility. Here, we show that induced association of ß-PIX with GIT1 is essential for the stimulation of IEC migration after wounding by activating Rac1. Levels of ß-PIX and GIT1 proteins and their association in differentiated IECs (line of IEC-Cdx2L1) were much higher than those observed in undifferentiated IECs (line of IEC-6), which was associated with an increase in IEC migration after wounding. Decreased levels of endogenous ß-PIX by its gene-silencing destabilized ß-PIX/GIT1 complexes, repressed Rac1 activity and inhibited cell migration over the wounded area. In contrast, ectopic overexpression of ß-PIX increased the levels of ß-PIX/GIT1 complexes, stimulated Rac1 activity, and enhanced intestinal epithelial restitution. Increased levels of cellular polyamines also stimulated ß-PIX/GIT1 association, increased Rac1 activity, and promoted the epithelial restitution. Moreover, polyamine depletion decreased cellular abundances of ß-PIX/GIT1 complex and repressed IEC migration after wounding, which was rescued by ectopic overexpression of ß-PIX or GIT1. These results indicate that ß-PIX/GIT1/Rac1 association is necessary for stimulation of IEC migration after wounding and that this signaling pathway is tightly regulated by cellular polyamines. NEW & NOTEWORTHY Our current study demonstrates that induced association of ß-PIX with GIT1 is essential for the stimulation of intestinal epithelial restitution by activating Rac1, and this signaling pathway is tightly regulated by cellular polyamines.

Inflammation and the Intestinal Barrier: Leukocyte-Epithelial Cell Interactions, Cell Junction Remodeling, and Mucosal Repair.

The intestinal tract is lined by a single layer of columnar epithelial cells that forms a dynamic, permeable barrier allowing for selective absorption of nutrients, while restricting access to pathogens and food-borne antigens. Precise regulation of epithelial barrier function is therefore required for maintaining mucosal homeostasis and depends, in part, on barrier-forming elements within the epithelium and a balance between pro- and anti-inflammatory factors in the mucosa. Pathologic states, such as inflammatory bowel disease, are associated with a leaky epithelial barrier, resulting in excessive exposure to microbial antigens, recruitment of leukocytes, release of soluble mediators, and ultimately mucosal damage. An inflammatory microenvironment affects epithelial barrier properties and mucosal homeostasis by altering the structure and function of epithelial intercellular junctions through direct and indirect mechanisms. We review our current understanding of complex interactions between the intestinal epithelium and immune cells, with a focus on pathologic mucosal inflammation and mechanisms of epithelial repair. We discuss leukocyte-epithelial interactions, as well as inflammatory mediators that affect the epithelial barrier and mucosal repair. Increased knowledge of communication networks between the epithelium and immune system will lead to tissue-specific strategies for treating pathologic intestinal inflammation.

Beyond endoscopic mucosal healing in UC: histological remission better predicts corticosteroid use and hospitalisation over 6†years of follow-up.

BACKGROUND: Endoscopic mucosal healing is an established treatment target for UC, yet the value of achieving histological remission remains unclear. AIMS: To evaluate histological remission compared to endoscopic mucosal healing for predicting patient outcomes in UC. METHODS: Blinded assessment of endoscopic and histological measures of disease activity was performed on patients with established UC at baseline. Concordance and prognostic values of endoscopic mucosal healing (defined by Baron score ≤1) and histological remission (defined by Truelove and Richards' index) for predicting outcomes of corticosteroid use, hospitalisation and colectomy were determined over a median 6 years follow-up, including κ statistics and Cox regression multivariate analysis. RESULTS: 91 patients with UC were followed up for a median 72 months (IQR 54-75 months). Overall, concordance between endoscopic and histological remission was moderate (κ=0.56, 95% CI 0.36 to 0.77); 24% patients had persistent inflammation despite endoscopic remission. Histological remission predicted corticosteroid use and acute severe colitis requiring hospitalisation over the follow-up period (HR 0.42 (0.2 to 0.9), p=0.02; HR 0.21 (0.1 to 0.7), p=0.02; respectively), whereas endoscopic mucosal healing did not (HR 0.86, 95% CI 0.5 to 1.7, p0.65; HR 0.83 95% CI 0.3 to 2.4, p0.74; respectively). CONCLUSIONS: Histological remission is a target distinct from endoscopic mucosal healing in UC and better predicts lower rates of corticosteroid use and acute severe colitis requiring hospitalisation, over a median of 6 years of follow-up. Our findings support the inclusion of histological indices in both UC clinical trials and practice, towards a target of 'complete remission'.

RNA sequencing shows transcriptomic changes in rectosigmoid mucosa in patients with irritable bowel syndrome-diarrhea: a pilot case-control study.

Our aim was to conduct a pilot case-control study of RNA expression profile using RNA sequencing of rectosigmoid mucosa of nine females with -diarrhea-predominant irritable bowel syndrome (IBS-D) with accelerated colonic transit and nine female healthy controls. Mucosal total RNA was isolated and purified, and next-generation pair-end sequencing was performed using Illumina TruSeq. Analysis was carried out using a targeted approach toward 12 genes previously associated with IBS and a hypothesis-generating approach. Of the 12 targeted genes tested, patients with IBS-D had decreased mRNA expression of TNFSF15 (fold change controls to IBS-D: 1.53, P = 0.01). Overall, up- and downregulated mRNA expressions of 21 genes (P = 10(-5) to 10(-8); P values with false detection rates are shown) were potentially relevant to IBS-D including the following: neurotransmitters [P2RY4 (P = 0.001), vasoactive intestinal peptide (VIP, P = 0.02)]; cytokines [CCL20 (P = 0.019)]; immune function [C4BPA complement cascade (P = 0.0187)]; interferon-related [IFIT3 (P = 0.016)]; mucosal repair and cell adhesion [trefoil protein (TFF1, P = 0.012)], retinol binding protein [RBP2 (P = 0.017)]; fibronectin (FN1, P = 0.009); and ion channel functions [guanylate cyclase (GUCA2B, P = 0.017), PDZ domain-containing protein 3 (PDZD3, P = 0.029)]. Ten genes associated with functions related to pathobiology of IBS-D were validated by RT-PCR. There was significant correlation in fold changes of the selected genes (Rs = 0.73, P = 0.013). Up- or downregulation of P2RY4, GUC2AB, RBP2, FNI, and C4BPA genes were confirmed on RT-PCR, which also revealed upregulation of farnesoid X receptor (FXR) and apical sodium-coupled bile acid transporter (IBAT/ASBT). RNA-Seq and RT-PCR analysis of rectosigmoid mucosa in IBS-D show transcriptome changes that provide the rationale for validation studies to explore the role of mucosal factors in the pathobiology of IBS-D.

Glucagon-like peptide-1 as a treatment for chemotherapy-induced mucositis.

BACKGROUND: Glucagon-like peptide-2 (GLP-2) has been suggested for the treatment of mucositis, but the peptide has also been shown to accentuate colonic dysplasia in carcinogen-treated mice. Recently, an effect on intestinal growth was discovered for glucagon-like peptide-1 (GLP-1), OBJECTIVE: To determine whether endogenous GLP-1 contributes to the healing processes and if exogenous GLP-1 has a potential role in treating mucositis. METHODS: Mice were injected with 5-fluorouracil (5-FU) or saline to induce mucositis and were then treated with GLP-1, GLP-2, GLP-2 (3-33), exendin (9-39) or vehicle. The mice were sacrificed 48 or 96 h after the 5-FU injections. The end points were intestinal weight, villus height, proliferation and histological scoring of mucositis severity. Rats were injected with 5-FU or saline, and after 48 h, blood was drawn and analysed for GLP-1 and GLP-2 concentration. RESULTS: GLP-1 and GLP-2 significantly prevented the loss of mucosal mass and villus height and significantly decreased the mucositis severity score in the duodenum and jejunum 48 h after chemotherapy. The effect was equivalent. Exendin (9-39) reduced the intestinal weight 96 h after chemotherapy. The GLP-1 levels in blood were increased more than 10-fold, and GLP-2 levels were increased sevenfold. CONCLUSIONS: GLP-1 and GLP-2 were secreted after intestinal injury, and recovery was delayed after treatment with exendin (9-39), indicating an important role for the peptides in the protection of the intestine from injury. GLP-1 treatment ameliorated mucositis, which suggests that mucositis and other acute intestinal disorders might benefit from treatment with GLP-1 analogues.

The Usefulness of Surgical Titanium Microclips for Mucosal Repair in the Frontal Sinus Using ORBEYE: A Technical Note.

Bifrontal craniotomy frequently involves opening the frontal sinus and mucosal injury. We report a new technique for mucosal repair in the frontal sinus using surgical titanium microclips. Six consecutive patients who underwent bifrontal craniotomy with frontal sinus exposure and mucosal injury underwent mucosal repair using surgical titanium microclips between April 2019 and August 2022. In all cases, the frontal sinus mucosa was peeled from the inner walls of the frontal sinus to ensure sufficient mucosal margin for clipping using ORBEYE. The repair was accomplished with the microclips in all cases. We also sealed the mucosal wound using fibrin glue and sufficiently filled the frontal sinus with bone debris, resulting in zero incidence of postoperative liquorrhea in all cases. Repairing the mucosa using surgical titanium microclips using ORBEYE may be a simple and quick technique when the frontal sinus mucosa is injured during craniotomy.

Melanin Nanoparticle-Modified Probiotics for Targeted Synergistic Therapy of Ulcerative Colitis.

Ulcerative colitis (UC) is a recurrent chronic mucosal inflammation disease whose most significant pathological characteristics are intestinal inflammation and damaged mucosal barrier induced by reactive oxygen/nitrogen species, abnormal immune microenvironment, and intestinal microecological imbalance. Oral probiotics are a living therapy for intestinal diseases, but their clinical application is hindered by poor bacterial biological activity and insufficient intestinal retention. Here, we developed a targeted oral formulation, functionalized probiotic Lf@MPB, with Lactobacillus fermentum (Lf) as the core and modified melanin nanoparticles (MNPs) on its surface through a click reaction of tricarboxyphenylboronic acid for synergistic therapy of UC. In vitro experiments showed that Lf@MPB not only possessed strong free radical scavenging ability, reduced cellular mitochondrial polarization, and inhibited apoptosis but also significantly enhanced the viability of Lf probiotics in simulated gastrointestinal fluid. Fluorescence imaging in vivo revealed the high accumulation of Lf@MPB at the site of intestinal inflammation in dextran sulfate sodium-induced UC mice. Moreover, in vivo results demonstrated that Lf@MPB effectively alleviated oxidative stress and inflammatory response and restored the intestinal barrier. In addition, 16S rRNA gene sequencing verified that Lf@MPB could increase the abundance and diversity of intestinal microbial communities and optimize microbial composition to inhibit the progression of UC. This work combines effective antioxidant and anti-inflammatory strategies with the oral administration of functionalized probiotics to provide a promising alternative for UC treatment.

An antibiotic-free platform for eliminating persistent Helicobacter pylori infection without disrupting gut microbiota.

Helicobacter pylori (H. pylori) infection remains the leading cause of gastric adenocarcinoma, and its eradication primarily relies on the prolonged and intensive use of two antibiotics. However, antibiotic resistance has become a compelling health issue, leading to H. pylori eradication treatment failure worldwide. Additionally, the powerlessness of antibiotics against biofilms, as well as intracellular H. pylori and the long-term damage of antibiotics to the intestinal microbiota, have also created an urgent demand for antibiotic-free approaches. Herein, we describe an antibiotic-free, multifunctional copper-organic framework (HKUST-1) platform encased in a lipid layer comprising phosphatidic acid (PA), rhamnolipid (RHL), and cholesterol (CHOL), enveloped in chitosan (CS), and loaded in an ascorbyl palmitate (AP) hydrogel: AP@CS@Lip@HKUST-1. This platform targets inflammatory sites where H. pylori aggregates through electrostatic attraction. Then, hydrolysis by matrix metalloproteinases (MMPs) releases CS-encased nanoparticles, disrupting bacterial urease activity and membrane integrity. Additionally, RHL disperses biofilms, while PA promotes lysosomal acidification and activates host autophagy, enabling clearance of intracellular H. pylori. Furthermore, AP@CS@Lip@HKUST-1 alleviates inflammation and enhances mucosal repair through delayed Cu2+ release while preserving the intestinal microbiota. Collectively, this platform presents an advanced therapeutic strategy for eradicating persistent H. pylori infection without inducing drug resistance.

Inhibition of Soluble Stem Cell Factor Promotes Intestinal Mucosal Repair.

BACKGROUND: Incidences of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, are escalating worldwide and can be considered a global public health problem. Given that the gold standard approach to IBD therapeutics focuses on reducing the severity of symptoms, there is an urgent unmet need to develop alternative therapies that halt not only inflammatory processes but also promote mucosal repair. Previous studies have identified increased stem cell factor (SCF) expression in inflamed intestinal mucosal tissues. However, the role that SCF plays in mediating intestinal inflammation and repair has not been explored. METHODS: Changes in the expression of SCF were evaluated in the colonic tissue of healthy mice and during dextran sodium sulfate (DSS)-induced colitis. Furthermore, mucosal wound healing and colitis severity were analyzed in mice subjected to either mechanical biopsy or DSS treatment, respectively, following intestinal epithelial cell-specific deletion of SCF or anti-SCF antibody administration. RESULTS: We report robust expression of SCF by intestinal epithelial cells during intestinal homeostasis with a switch to immune cell-produced SCF during colitis. Data from mice with intestinal epithelial cell-specific deletion of SCF highlight the importance of immune cell-produced SCF in driving the pathogenesis of colitis. Importantly, antibody-mediated neutralization of total SCF or the specific SCF248 isoform decreased immune cell infiltration and enhanced mucosal wound repair following biopsy-induced colonic injury or DSS-induced colitis. CONCLUSIONS: These data demonstrate that SCF functions as a pro-inflammatory mediator in mucosal tissues and that specific neutralization of SCF248 could be a viable therapeutic option to reduce intestinal inflammation and promote mucosal wound repair in individuals with IBD.

Our investigation demonstrates that blocking cleavable SCF248 isoform by administration of specific stem cell factor antibodies enhances healing of the intestinal mucosa and restores critical barrier function, suggesting an alternative therapeutic option to treat individuals with active IBD.

Folic acid-modified lactoferrin nanoparticles coated with a laminarin layer loaded curcumin with dual-targeting for ulcerative colitis treatment.

Curcumin (CUR) is a promising natural compound in ulcerative colitis (UC) treatment, but limited by its low oral bioavailability and poor targeting ability. Therefore, given the targeting action of lactoferrin (LF) by binding to the LF receptors of intestinal epithelial cells (IECs) and of folic acid (FA) by binding to the FA receptors of macrophages, we developed an oral dual-targeting nanosystem. Laminarin (LA)-coated, FA-modified LF nanoparticles (NPs) were used to encapsulate CUR (LA/FA/CUR-NPs) with a food-grade, enzyme-sensitive, and dual-targeting capacity. For the generated NPs, LF improved the loading efficiency of CUR (95.08 %). The LA layer could improve the upper gastrointestinal tract stability of the NPs while improve drug release around colon lesion through ß-glucanase digestion. Based on the cellular uptake evaluation, FA/CUR-NPs were capable of specifically targeting colonic epithelial cells and macrophages through LF and FA ligands, respectively, to enhance the uptake efficiency. Moreover, based on the advantage of the dual-targeting strategy, oral administration of FA/CUR-NPs obviously reduced colitis symptoms by alleviating inflammation, accelerating colonic mucosal barrier repair and restoring the balance of the intestinal microbiota. This dual-targeted nanodesign corresponded to the multi-bioresponsibilities of CUR, thus offering a promising approach in UC treatment.

miR-29c-3p Accelerates Mucosal Repair in Dextran Sodium Sulfateinduced Ulcerative Colitis Mice through the KDM6B/H3K27me3/LDHA Axis.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory intestinal disorder featured by mucosal injury. MicroRNAs (miRNAs) play a role in the pathogenesis underlying UC. OBJECTIVES: This study was conducted to investigate the role of miR-29c-3p in a dextran sodium sulfate (DSS)-induced UC mouse model and provide targets for UC treatment. METHODS: The UC mouse model was established by DSS induction. The expression levels of miR- 29c-3p, lysine-specific demethylase 6B (KDM6B), zonula occludens-1 (ZO-1), Occludin, and lactate dehydrogenase A (LDHA) were detected by real-time quantitative polymerase chain reaction or Western blot assays. The mucosal injury was evaluated by disease activity index (DAI), colon length, Hematoxylin-Eosin staining, and fluorescein isothiocyanate-glucan permeability test. The binding between miR-29c-3p and KDM6B and the occupation of KDM6B or trimethylated H3 lysine 27 (H3K27me3) on the LDHA promoter were analyzed by the dual-luciferase and chromatinimmunoprecipitation assays. RESULTS: miR-29c-3p was downregulated while KDM6B and LDHA were upregulated in DSS mice. miR-29c-3p overexpression reduced DAI and inflammatory cell infiltration while increasing colon length, intestinal permeability, and levels of ZO-1 and Occludin. miR-29c-3p inhibited KDM6B expression and increased H3K27me3 occupation on the LDHA promoter, thus inhibiting LDHA transcription. Overexpression of KDM6B or LDHA averted the protective role of miR-29c-3p upregulation in mucosal injury. CONCLUSION: miR-29c-3p limited KDM6B expression and increased the H3K27me3 occupation on the LDHA promoter to enhance LDHA transcription, moderating mucosal injury and delaying UC progression.

Trans-anethole Ameliorates Intestinal Injury Through Activation of Nrf2 Signaling Pathway in Subclinical Necrotic Enteritis-Induced Broilers.

This study was conducted to investigate the alleviative effects of trans-anethole (TA) on intestinal oxidative stress by enhancing the activities of intestinal antioxidant enzymes and activating the Nrf2 signaling pathway in subclinical necrotic enteritis (NE) infected broilers. A total of 192 1-day-old male Arbor Acres broilers were randomly allocated into three treatment groups: (1) control (CON); (2) subclinical NE challenge (NE); (3) NE challenge + 600 mg/kg TA (NE+TA600). Subclinical NE was induced by oral administration of live coccidiosis vaccine containing 2 × 104 oocysts at 10 days of age and 2 ml of Clostridium perfringens type A solution (3 × 108 CFU/ml) daily from days 14 to 19. The results showed that NE infection led to a severe decline (p < 0.05) in the final body weight (BW) and average daily gain (ADG), but an increase (p < 0.05) in feed/gain (F/G) of broilers at day 10-21 and day 1-21 compared with the control group. TA administration improved (p < 0.05) the growth performance of NE birds. The intestinal villus height (VH) and villus height/crypt depth (VH/CD) were reduced (p < 0.05) by NE challenge as compared with those of the control group, which was elevated by TA administration. Subclinical NE infection decreased (p < 0.05) serum activities of total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC), and jejunal and ileal glutathione peroxidase (GSH-PX), and T-SOD activity as well as T-AOC in the jejunum, while TA interventions positively elevated that (p < 0.05). Administration of TA protected the intestine against oxidative stress through up-regulation of intestinal nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway as compared with the NE group (p < 0.05). In addition, dietary inclusion of TA elevated (p < 0.05) mRNA abundance of c-mesenchymal-epithelial transition factor (c-Met), jejunal epidermal growth factor receptor (EGFR), and transforming growth factor-beta 1 (TGF-ß1) in the jejunum and ileum of birds after subclinical NE challenge. In conclusion, 600 mg/kg of TA may be a promising tool to prevent and control subclinical NE by increasing intestinal antioxidant status in broilers.

YAP Activates STAT3 Signalling to Promote Colonic Epithelial Cell Proliferation in DSS-Induced Colitis and Colitis Associated Cancer.

Background and Aims: Yes-associated protein (YAP) is a key transcriptional coactivator of cell proliferation and differentiation. In this study, we sought to identify the roles of YAP in colonic epithelial regeneration and tumourigenesis. Methods: Murine DSS-induced colitis and YAP overexpression models were constructed via lentiviral intraperitoneal injection. Stable YAP-overexpressing cells, protein immunoprecipitation, and ChIP were used to deeply explore the molecular mechanism. Results: We found that the expression of YAP was dramatically diminished in the colonic crypts during the acute colitis phase, while YAP was strikingly enhanced to initiate tissue repair after DSS withdrawal. Overexpressing YAP in mice drastically accelerated epithelial regeneration, presenting with more intact structural integrity and reduced inflammatory cell infiltration in the mucosa. Further mechanistic studies showed that the expression of YAP in the nucleus was significantly increased by 2 h post-DSS removal, accompanied by upregulated protein levels of activated STAT3. Overexpression of YAP (YAPWT) elevated the expression of activated STAT3 and its transcriptional targets and strengthened the proliferation and "wound healing" ability of colonic cells. However, these effects were reversed when STAT3 was silenced in YAPWT cells. Moreover, YAP could directly interact with STAT3 in the nucleus, and c-Myc and CyclinD1 were the transcriptional targets. Finally, during colitis-associated cancer (CAC), YAPWT promoted the progression of CAC, while the phosphomimetic YAP downregulated the expression of STAT3 and inhibited the development and progression of CAC. Conclusion: YAP activates STAT3 signalling to facilitate mucosal regeneration after DSS-induced colitis. However, excessive YAP activation in the colonic epithelium promotes CAC development.

ZINC40099027 activates human focal adhesion kinase by accelerating the enzymatic activity of the FAK kinase domain.

Focal adhesion kinase (FAK) regulates gastrointestinal epithelial restitution and healing. ZINC40099027 (Zn27) activates cellular FAK and promotes intestinal epithelial wound closure in vitro and in mice. However, whether Zn27 activates FAK directly or indirectly remains unknown. We evaluated Zn27 potential modulation of the key phosphatases, PTP-PEST, PTP1B, and SHP2, that inactivate FAK, and performed in vitro kinase assays with purified FAK to assess direct Zn27-FAK interaction. In human Caco-2 cells, Zn27-stimulated FAK-Tyr-397 phosphorylation despite PTP-PEST inhibition and did not affect PTP1B-FAK interaction or SHP2 activity. Conversely, in vitro kinase assays demonstrated that Zn27 directly activates both full-length 125 kDa FAK and its 35 kDa kinase domain. The ATP-competitive FAK inhibitor PF573228 reduced basal and ZN27-stimulated FAK phosphorylation in Caco-2 cells, but Zn27 increased FAK phosphorylation even in cells treated with PF573228. Increasing PF573228 concentrations completely prevented activation of 35 kDa FAK in vitro by a normally effective Zn27 concentration. Conversely, increasing Zn27 concentrations dose-dependently activated kinase activity and overcame PF573228 inhibition of FAK, suggesting the direct interactions of Zn27 with FAK may be competitive. Zn27 increased the maximal activity (Vmax ) of FAK. The apparent Km of the substrate also increased under laboratory conditions less relevant to intracellular ATP concentrations. These results suggest that Zn27 is highly potent and enhances FAK activity via allosteric interaction with the FAK kinase domain to increase the Vmax of FAK for ATP. Understanding Zn27 enhancement of FAK activity will be important to redesign and develop a clinical drug that can promote mucosal wound healing.

ß-1,3-d-Glucan based yeast cell wall system loaded emodin with dual-targeting layers for ulcerative colitis treatment.

Herein, a ß-1,3-d-glucan based microcarrier, yeast cell wall microparticles (YPs), was used to develop a food-source-based nano-in-micro oral delivery system for ulcerative colitis (UC) treatment. Briefly, lactoferrin (Lf), which targets intestinal epithelial cells, was used to encapsulate emodin (EMO) to form nanoparticles (EMO-NPs), and then loaded into YPs with the natural macrophages targeting ability, forming a final formula with two outer-inner targeting layers (EMO-NYPs). These dual-targeting strategy could enhance the dual-effects of EMO in anti-inflammatory and mucosal repair effects respectively. As expected, cell uptake assessment confirmed that EMO-NPs and EMO-NYPs could target on the Lf and dection-1 receptors on the membranes of Caco-2 cells and macrophages, respectively. Importantly, EMO-NYPs showed the best anti-UC effects compared to EMO-NPs and free EMO, by inhibiting NF-κB pathway to anti-inflammation and promoting intestinal mucosa repair via MLCK/pMLC2 pathway. The results show that EMO-NYPs are a promising food-based oral delivery system in anti-UC.